Read YAML file

• serde
• serde_yml
• from_reader
• as_i64
• as_str
• struct

• TODO: if the number of dashes at the top is not correct (e.g. 4, the parser will panic, how to handle this properly?)

Hello World!
3
data = Point { x: 1, y: 2, text: "Hello World!" }
3
Hello World!

---
x: 1
y: 2
text: Hello World!

[package]
name = "read-yaml-file"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
serde = { version = "1.0", features = ["derive"] }
serde_yml = "0.0.12"


```rust
use std::fs::File;

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, Debug)]
struct Point {
    x: i32,
    y: i32,
    text: String,
}

fn main() {
    read_any_yaml();
    read_struct_yaml();
}

fn read_any_yaml() {
    let filename = "data.yaml";
    match File::open(filename) {
        Ok(file) => {
            let data: serde_yml::Value = serde_yml::from_reader(file).expect("YAML parsing error");
            dbg!(&data);

            let text = match data.get("text") {
                Some(val) => val.as_str().unwrap(),
                None => panic!("Field text does not exist"),
            };
            println!("{}", text);

            let x = match data.get("x") {
                Some(val) => val.as_i64().unwrap(),
                None => panic!("Field x does not exist"),
            };
            let y = match data.get("y") {
                Some(val) => val.as_i64().unwrap(),
                None => panic!("Field y does not exist"),
            };
            println!("{}", x + y);
        }
        Err(error) => {
            println!("Error opening file {}: {}", filename, error);
        }
    }
}

fn read_struct_yaml() {
    let filename = "data.yaml";
    match File::open(filename) {
        Ok(file) => {
            let data: Point = serde_yml::from_reader(file).unwrap();
            println!("data = {:?}", data);
            println!("{}", data.x + data.y);
            println!("{}", data.text);
            assert_eq!(data.x, 1);
            assert_eq!(data.y, 2);
            assert_eq!(data.text, "Hello World!");
        }
        Err(error) => {
            println!("Error opening file {}: {}", filename, error);
        }
    }
}

Hello World! 3 data = Point { x: 1, y: 2, text: "Hello World!" } 3 Hello World!

<style>
  footer {
    text-align: center;
    text-wrap: balance;
    margin-top: 5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }
  footer p {
    margin: 0;
  }
</style>
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